4U77

BTB domain from Drosophila CP190

4U77 の概要

• エントリーDOI: 10.2210/pdb4u77/pdb
• 分子名称: Centrosome-associated zinc finger protein CP190, GLYCEROL, DIMETHYL SULFOXIDE, ... (4 entities in total)
• 機能のキーワード: btb fold, dimer, peptide binding groove, transcription
• 由来する生物種: Drosophila melanogaster (Fruit fly)
• 細胞内の位置: Nucleus: Q24478
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 16796.43

構造登録者

Allemand, F.,Cohen-Gonsaud, M.,Labesse, G.,Nollmann, M. (登録日: 2014-07-30, 公開日: 2014-08-13, 最終更新日: 2024-05-08)

主引用文献

Vogelmann, J.,Le Gall, A.,Dejardin, S.,Allemand, F.,Gamot, A.,Labesse, G.,Cuvier, O.,Negre, N.,Cohen-Gonsaud, M.,Margeat, E.,Nollmann, M.
Chromatin Insulator Factors Involved in Long-Range DNA Interactions and Their Role in the Folding of the Drosophila Genome.
Plos Genet., 10:e1004544-e1004544, 2014

PubMed Abstract: Chromatin insulators are genetic elements implicated in the organization of chromatin and the regulation of transcription. In Drosophila, different insulator types were characterized by their locus-specific composition of insulator proteins and co-factors. Insulators mediate specific long-range DNA contacts required for the three dimensional organization of the interphase nucleus and for transcription regulation, but the mechanisms underlying the formation of these contacts is currently unknown. Here, we investigate the molecular associations between different components of insulator complexes (BEAF32, CP190 and Chromator) by biochemical and biophysical means, and develop a novel single-molecule assay to determine what factors are necessary and essential for the formation of long-range DNA interactions. We show that BEAF32 is able to bind DNA specifically and with high affinity, but not to bridge long-range interactions (LRI). In contrast, we show that CP190 and Chromator are able to mediate LRI between specifically-bound BEAF32 nucleoprotein complexes in vitro. This ability of CP190 and Chromator to establish LRI requires specific contacts between BEAF32 and their C-terminal domains, and dimerization through their N-terminal domains. In particular, the BTB/POZ domains of CP190 form a strict homodimer, and its C-terminal domain interacts with several insulator binding proteins. We propose a general model for insulator function in which BEAF32/dCTCF/Su(HW) provide DNA specificity (first layer proteins) whereas CP190/Chromator are responsible for the physical interactions required for long-range contacts (second layer). This network of organized, multi-layer interactions could explain the different activities of insulators as chromatin barriers, enhancer blockers, and transcriptional regulators, and suggest a general mechanism for how insulators may shape the organization of higher-order chromatin during cell division.

PubMed: 25165871
DOI: 10.1371/journal.pgen.1004544

実験手法

X-RAY DIFFRACTION (2.03 Å)